Question

According to the equation for this chemical reaction, what does the 2 in front of 2Ag tell us?

Answer 1

Answer:

It tell us that it's necessary 2 moles of Ag in the stoichiometric proportion of the reaction.

Explanation:

The equation of a chemical reaction is a representation of the ideal reaction: 100% yield of the products and without parallel reactions. So, the equation presents the stoichiometric quantities of the substance. For example, for a generic reaction:

A + 2B → 3C

It says that it's necessary 1 mol of A and 2 moles o B to form 3 moles of C. Thus, the numbers before the substances represents the stoichiometric number of moles of that substance.

Answer 2

The number of molecules involved in the reaction, in this case, the number of Ag atoms involved.